One way flow ventilator damper



g- 1965 c. w. EICHHORN ONE WAY FLOW VENTILATOR DAMPER Filed March 1,1965 INVENTOR. CHARLES W. EICHHORN United States Patent 3,2ii2,083 ONEWAY FLOW VENTHLATOR DAMPER Charles W. Eichhorn, 26718A (lair CrossingRoad, Newhall, Calif. Filed Mar. 1, 1965, Ser. No. 436,067 Claims. (Cl.98-116) end of an exhaust flue or vent associated with an exhaust fanand which is readily displaceable to any air flow into the vent or flueand which operates to at least substantially prevent air flow in theopposite direction.

Another object of the invention is to provide a damper embodying theabove objective which is formed from a single piece of light weight,resilient sheet material.

A further object of the invention is to provide a oneway damper meanswhich is capable of installation on existing exhaust fan equipmentwithout the need of any special tools or other equipment.

With the foregoing objects in view, together with such additionalobjects and advantages as may subsequently appear, the invention residesin the provision of a oneway damper means which is responsive todifferential air flows in one direction only as disclosed in thefollowing specification of certain presently preferred embodiments ofthe invention, reference being bad to the accompanying drawings whichform apart of said specification. and in which drawings:

FIG. 1 is a plan view of a one-way damper means constituting a firstembodiment of the invention shown in its normal position of repose,

FIG. 2 is a plan view of a second embodiment of the invention also shownin its normal position of repose,

FIG. 3 is a perspective view of the damper means constituting the firstembodiment of the invention as distorting an air flow through the flueor vent with which the said first embodiment of the invention may beassociated,

FIG. 4 is a transverse sectional view of a portion of a building ceilingshowing an exhaust fan installed in a vent leading from the ceiling of aroom and with the first embodiment of the invention installed inconnection therewith, the said first embodiment being shown as extendedin response to air flow initiated by operation of the exhaust fan,

FIG. 5 is a perspective view of the second embodiment of the inventionas extended in response to air flow, and

FIG. 6 is a transverse sectional view similar to FIG. 4 showing thesecond embodiment installed and caused to be extended and opened by adraft or air flow created by the operation. of the associated exhaustfan.

Referring firs-t to FIG. 4, there is shown a ceiling exhaust faninstallation which is typical of those with which the invention isproposed to be associated. Exhaust fans and associated vents of thistype are commonly employed in kitchens and bathrooms of dwelling housesand apartments, the illustrated installation comprising a metal flue orvent A extending from an opening B in the ceiling to a suitable openingin the roof (not shown). Slightly above the lower end of the flue andwithin the flue there is mounted a vertical shaft electric motor Cdriving a propeller type fan D in a direction of rotation to draw airfrom the room upwardly through the flue. At the lower end thereof, theflue vent is concealed by an ornamental metal or plastic grille Eremovably secured by any suitable means as, for example, by a stud Fprojecting downwardly from the motor through the grille and having athreaded end disposed below the grille engaged by a hand knob or nut Gholding the periphery of the grille against the ceiling surface.

Referring next to FIGS. 1 and 3 together with FIG. 4, the firstembodiment of the invention comprises a thin, flat, generallyrectangular plate 1 of light weight, somewhat resilient metal orplastic, the perimeter shown in FIGS. 1 and 3 including slightly convexside edges 2 and rounded corners 3 to accommodate the inner perimeter ofthe edges of the grille. The metal, for example, may be temperedaluminum of about .015" thickness and any sheet plastic used would havea comparableweight and resilience. The plate 1 is installed between theupper face of the grille E and the ceiling and is provided with a firsthole 4 at the center thereof to which the stud F' extends; said centralhole serving as a starting point or a narrow spiral cut or slot 5 ofsome 2 /2 convolutions terminating at a radial distance which is lessthan the smallest radial dimension of the flue opening. The plate may befurther provided with a second hole 6 laterally offset from the centerhole to accommodate a pull chain for those fans which are operated by apull chain switch as shown at H rather than by a wall switch, both typesof fan control being commonly used on difierent installations.

Referring again to FIG. 4, theplate is shown .in the. attitude occupiedwhen the fan is in operation with the convolutions separated from oneanother as shown in FIG. 3, the perimeter of the plate being restrainedby engagement between the grille and the ceiling. When the motor and fanare not in operation, the resilience of the material of the plate bringsthe convolutions into the plane of the perimeter thereof thus effectinga substantial closure of the vent against down drafts therethrough sincesuch down drafts would merely displace the convolutions downwardly intoengagement with the upper surface of the grille affording little, if anyroom for the passage of air therethrough. It is, of course, essentialthat the material of this damper element be sufficiently light to bereadily displaced by the draft induced by action of the fan while at thesame time having sufficient resilience to normally lie in a single planewhen in repose.

FIGS. 2, 5 and 6 illustrate a second embodiment of the invention inwhich the damper element, instead of being mounted against the ceilingsurface by the grille and having the center portion thereof movable inresponse to air flow, is mounted at its center on the stud whichsupports the grille with the convolutions and peripheral portion beingyieldable up into the flue in response to exhaust fan induced air flow.In this form of the invention, the damper element comprises a circularplate 10 formed of the same materials as the plate 1 of the firstdescribed embodiment, said circular plate having a central hole 11extending therethrough for reception of the: stud F. The hole 11,however, serves as the mounting and securing means and to this end, thestud F is provided with a sleeve 12 extending from the motor to theplane in which the plate It is to be located, said sleeve being ofgreater diameter than the hole 11. The nut G which secures the grille Eagainst the ceiling, also clamps the plate. 10

plate, like the plate 1, into a weak spiral spring having a i normal orreposed position in which the convolutions lie in the same plane andserve as a damper preventing down drafts through the exhaust fan flue byengagement with the adjacent upper face of the grille. If desired, ahole 14 for a pull chain switch may be provided. On operation of theexhaust fan, however, the induced flow of air will displace theconvolutions substantially as shown in FIGS. and 6 opening the damperand allowing substantially free flow of air therethrough.

Thus there has been provided a reverse flow preventing damper meanswhich is particularly useful for ceiling exhaust fan vents and wihch iscapable of being installed by merely removing the removable grilleassociated with such exhaust fans. Moreover, since it is formed of asingle sheet of resilient metal or plastic, this damper is economical tomanufacture and when it is in its normal position of repose it affords asatisfactory barrier for down drafts from wind or other conditions Also,while it is useful for and will be more commonly employed for ceilingvents, the resilience of the plate obviously permits it to be employedin vents or flues which are located in walls rather than in the ceiling.

While in the foregoing specification there has been disclosed certainpresently preferred embodiments of the invention, such disclosure hasbeen by Way of example, and the invention will be understood to include,as well, all such changes and modifications as shall come Within thepurview of the appended claims.

I claim:

1. A normally closed room exhaust vent damper means for use with a venthaving a grille extending thereacross, said damper means comprising anormally fiat, resilient sheet of material impervious to air and havinga portion thereof resiliently displaceable out of the plane of saidsheet when in its normal fiat condition in response to a pressuredifferential on opposite sides thereof to create opening for air passagetherethrough, and means for mounting said sheet at the side of thegrille adjacent to the vent opening; said sheet including a portionthereof positioned to permit said sheet to be secured in operativeposition at said side of the grille by the means by which the grille ismounted across the vent opening.

2. The combination as claimed in claim 1 in which said damper means isdisposed in such close adjacency to the adjacent surface of said grilleas to be preveneted thereby from displacement in response to a pressurecondition tending to cause air fiow through the vent into the room.

3. The combination as claimed in claim 2 in which said damper means islarger than the vent and has the peripheral edge thereof confinedbetween the grille and the surface through which the vent extends.

4. The combination as claimed in claim 2 in which said damper means hasa peripheral dimension and configuration closely fitting the vent, inwhich a mounting means for the grille is disposed at the center of thevent, and in which said damper means is secured at the center thereof onthe mounting means for the grille.

5. A damper means as claimed in claim 1 in which said sheet has thecentral portion thereof formed into a spiral by a spiral cut of morethan one convolution extending from a point near the center of the sheetto a point adjacent the peripheral edge of the sheet.

References Cited by the Examiner UNITED STATES PATENTS 1,053,507 2/13I-Iiett 98-119 2,368,320 1/45 Norris 98ll6 X 3,063,461 11/62 Rudolph.

FOREIGN PATENTS 5,502 12/80 Great Britain. 166,131 2/ 34 Switzerland.

WILLIAM F. ODEA, Acting Primary Examiner. JOHN F. OCONNOR, Examiner.

1. A NORMALLY CLOSED ROOM EXHAUST VENT DAMPER MEANS FOR USE WITH A VENTHAVING A GRILLE EXTENDING THEREACROSS, SAID DAMPER MEANS COMPRISING ANORMALLY FLAT, RESILIENT SHEET OF MATERIAL IMPERVIOUS TO AIR AND HAVINGA PORTION THEREOF RESILIENT DISPLACEABLE OUT OF THE PLANE OF SAID SHEETWHEN IN ITS NORMAL FLAT CONDITION IN RESPONSE TO A PRESSURE DIFFERENTIALON OPPOSITE SIDES THEREOF TO CREATE OPENING FOR AIR PASSAGETHERETHROUGH, AND MEANS FOR MOUNTING SAID SHEET AT THE SIDE OF THEGRILLE ADJACENT TO THE VENT OPENING; SAID SHEET INCLUDING A PORTIONTHEREOF POSITIONED TO PERMIT SAID SHEET TO BE SECURED IN OPERATIVEPOSITION AT SAID SIDE OF THE GRILLE BY THE MEANS BY WHICH THE GRILLE ISMOUNTED ACROSS THE VENT OPENING.